Wetting and detergent composition



Patented July 24, 1951 WETTING AND DETERGENT COMPOSITION Emil I A. Vitalis, Springdale, Conn., assignor to American Cyanamid Company, New York, N. Y., a corporation of Maine No Drawing. Application November 3, 1949, Serial No. 125,397

This invention relates to wetting and detergent and detergent processes in which these compositions are used.

It is known that the higher monoalkyl sulfosuccinates, when used in the form of their salts with monovalent salt-forming compounds, possess good wetting and particularly good detergent properties. However, the salts of monoesters of sulfosuccinic acid with alcohols of 12 or more carbon atoms, which is the minimum chain length for good detergency, possess relatively low solubility in water, which is a serious disadvantage. It is a principal object of the present. invention to provide for this class of compounds solubilizing agents which improve their water solubility and thus increase their usefulness as wetting agents and detergents. A further object resides in the provision of readily soluble pastes or Powders containing the higher monoalkyl sulfosuccinates in a solubilized and therefore water-dispersible condition. Still further objects of the invention will be apparent from the following detailed description of preferred embodiments thereof.

As is noted above the sodium, potassium, ammonium, ethanolamine and similar salts of the higher monoalkyl sulfosuccinates in which the alkyl radical contains 12 or more carbon atoms are only slightly soluble in water. The solubility of the disodium salts, which is given in the following table, is typical of the corresponding salts of potassium and ammonium as well.

solo 1 :35a

gms. cc.

oi Solution at 30 C.

Monoalkyl Disodium sulfosuccinate 2 Claims. (Cl. 252161) substances of hydrocarbon nature boiling at 39 C. to 96 C. at 0.3 mm. of mercury pressure and therefore containing about 14-16 carbon atoms, and about 5-8% of higher boiling materials, possibly higher alcohols. This mixture is hereinafter designated as Ammecol," which is its commercial name.

Attempts have been made to solubilize these and similar compounds by adding water-soluble alcohols, ethers of ethylene glycol and other agents which are known to solubilize the higher dialkyl sulfosuccirates. However, it was found that these alcohols and ethers actually reduce the water solubility of the alkali metal and ammonium salts of higher monoalkyl sulfosuccinates.

I have now discovered that water-soluble cobalt salts such as cobalt sulfate, cobalt chloride, cobalt nitrate, and the like are excellent solubilizing agents for the higher monoalkyl sulfosuccinate salts. This is a remarkable discovery, for the addition of the corresponding salts of other alkali metals such as sodium or potassium sulfate or chloride causes precipitation of the higher monoalkyl sulfosuccinate salts instead of solubilizing them. I have found, however, that I can prepare stable aqueous solutions containing from about 1% to about 30% of the wetting agents, depending on the particular alcohol present in the sulfosuccinate ester, as well as water-soluble concentrated aqueous pastes containing about 30-70% of the wetting agents, and even watersoluble dry powders containing the higher monoalkyl sulfosuccinate salts together with inorganic salts of the type of sodium sulfate, sodium chloride and the like by incorporating therein suitable quantities of cobalt salts which ionize in aqueous solution.

The monoalkyl sulfosuccinate salts which are solubilized by cobalt salts in accordance with the present invention have the following formula H MOiS.C.COOM

octadecyl, octadecenyl or other alcohols containwith dodecyl, tetradecyl,

ing 12 or more carbon atoms at about 100-110 C. to form the monoester, followed by sulfonating this ester to form the sulfosuccinate. Preferably the sulfonation is carried out by heating the ester with an aqueous solution of sodium sulfite,

or sodium metablsilfite, or the corresponding potassium or ammonium compounds. By this method the alkali metal and ammonium salts of the monoalkyl sulfosuccinic acid esters are obtained directly.

The corresponding salts of ethanolamine and other bases are preferably produced by first esterifying an alcoholic solution of the alkali metal or ammonium sulfosuccinates, whereby 1 stirring until the salt formation is complete.

Salts of organic bases such as methyl amine, ethyl amine, ethanolamine and the like may also be prepared by the same method.

For many purposes it is desirable to prepare the higher monoalkyl sulfosuccinates in the form of dry, water-dispersible powders. Heretofore this has not been possible, for upon evaporation of their solutions in water or organic solvents the compound s form a white pasty mass similar in texture to ordinary soap. The compounds are precipitated from their aqueous solutions by the addition of ammonium, sodium or potassium salts, and therefore the addition of sodium or potassium sulfate or chloride to form a dry, freefiowing powder could not be resorted to. v

Another important feature of the present invention is the discovery that the solubilizing action of water-soluble inorganic cobalt salts persists even in the presence of sodium sulfate,

sodium chloride and other salts which would ordinarily precipitate the higher monoalkyl sulfosuccinate salts from their water solutions. This discovery has enabled me to prepare dry,

free-flowing powders containing the higher monoalkyl sulfosuccinate salts in admixture with water-soluble alkali metal compounds other than cobalt compounds, or in admixture.

with water-soluble ammonium compounds, which powders are readily soluble in cold water. No material change in theratio of cobalt salt to monoalkyl sulfosuccinate salt need be made when other water-soluble salts are added; i. e. the solubilizing action of the cobalt salts is the same in the presence of sodium sulfate, sodium,

chloride and the like as it is in the absence of these salts. However, it has been found that while the upper limit of diluent which may be employed depends entirely on the desired concentration of wetting agent in the dry mixture, the lower limit of diluent is not essentially less than 40% of the mixture. For example, when a dry mixture is prepared containing more than about 60% of ,the monoalkyl sulfosuccinate, the material is not easily soluble in cold water; for this reason dry mixtures containing in excess of about of monoalkyl sulfosuccinate are not included within the purview of this invention.

In practicing the invention, the amounts of cobalt to be employed vary according to the original water solubility of the various monoalkyl sulfosuccinate salts. It will be readily apparent that dodecyl disodium sulfosuccinate, having a water solubility of 4.5 grams per cc., will require the addition of less cobalt salt than will disodium hexadecyl sulfosuccinate, for example, having a water solubility of 0.2 gram per 100 cc., in the preparation of aqueous solutions of 10% wetting agent content. The following table sets forth the increase in aqueous solubility of various sulfosuccinate salts induced by optimum molar addition of cobalt salts. M01, as expressed in the description of the present invention, may be defined as the gram ionic equivalent of the salt employed. r

The sulfosuccinate mixture above referred to is that prepared from Ammecol.

As is common in the case of the solubility of salts, higher solution temperatures result in an increase of the solubilityof the various salts. In the .case of the present invention, such variations in solution temperatures permit the use of smaller amounts of the solubilizing cobalt salts. For this reason, the lower limits of such salt additions may in some cases and for some purposes be within the range of from 0.25 to 0.5 mol per mol of sulfosuccinate salt employed. On the other hand, while there is no absolute upper limit. of cobalt salt addition since the solubilizing agent does .not interfere with the wetting and detergent properties of monoalkyl sulfosuccinates, for most commercial applications not more than about 7-10 mols of cobalt salt should be employed for each mo] of sulfosuccinate. Moreover, I have found that the most preferable quantity of cobalt salt to be employed is from 0.25 mol to 2.0 mols for each mol of the sulfosuccinate depending on its water solubility.

Conversely, in preparing aqueous pastes and dry powders containing water-soluble inorganic salts of monovalent metals such as sodium and potassium, larger amounts of cobalt salts may of course be used, although amounts substantially larger than those given in the above table are not usually necessary.

It is evident, therefore, that the invention in its broader aspects is not limited to the use of large quantities of the cobalt salts but that relatively small proportions of these salts may be used if desired.

The invention will be illustrated in greater detail by the following specific examples. It should be understood, however, that although these examples may describe in detail certain specific features of the invention, they are given primarily for purposes of illustration and the invention in its br ader aspects is not limited thereto. All parts given are by weight.

Example 1 and 4.6 parts of C0804. prepare an aqueous solution containing 8% of the sulfosuccinate salt. The mixture was completely soluble, and remained clear at temperatures of from about 6 to 0., whereas the same sulfcsuccinate salt is normally only 0.2% soluble at temperatures of or less than 35 C.

Example 2 A dry, free-flowing powder was obtained'by drying to 100 parts an aqueous mixture comprising 116 parts of a 30% gel of the disodium monoalkyl sulfosuccinate mixture employed in Example 1, 5.5 parts ofCoSOa, and 69 parts of NazSOa The dried powder formed clear solu- The paste was used to.

tions with water when used in concentrations up to 8%.

Example 3 i To 100 cc. of a 2% aqueous dispersion-of dipotassium cetyl sulfosuccinate was added 5.2 cc. of a 10% aqueous solution of CoClz (1:1 molar ratio). Within a short period of time the initially cloudy dispersion became clear, indicating that a true solution of the sultosuccinate had been obtained.

Example 4 To 100 cc. of a 2% aqueous dispersion of diammonium cetyl sultosuccinate was added 12.! cc. of a 10% aqueous solution of C0(NO3) 2.6H2O (1:1 molar ratio). After a short period of time the initially cloudy dispersion became clear, indicating that a true solution of the sulfosuccinate had been obtained.

Example 5 To 100 cc. of 5% disodium oleyl sulfosuccinate was added 5.4 cc. of a 10% aqueous solution of C0012 (1:1 molar ratio). Within a short period ot time the initially cloudy dispersion became clear, indicating that a true solution of the suliosuccinate had been obtained.

Example 6 A dry, free-flowing powder was prepared by drying to 100 parts an aqueous mixture consisting of 116 parts of a 30% gel of a disodium monoalkyl sulfosuccinate mixture prepared from Ammecol, 5.5 parts of C0304, and 69 parts of NaCl. The dried powder formed clear solutions with water when used in concentrations up to 8 This is a continuation-in-part of my copending application Serial No. 626,579, filed November 3, 1945, and which is now abandoned.

I claim:

1. A wetting and detergent composition comprising essentially a surface active material which is a monoalkyl sulfosuccinate having the formula Mose-o 00M in which M is a member of the group consisting of alkali metal and ammonium radicals and both Ms are the same, and R is an alkyl radical of from 12 to 18 carbon atoms, and a water-soluble inorganic cobalt salt which is capable of increasing the water solubility of the monoalkyl sulfosuccinate, said cobalt salt being present in an amount the minimum range of which is from 0.25 mol to 2.0 mols and the maximum amount is 10 mols for each mol of the sulfosuccinate.

2. A wetting and detergent composition com prising essentially a surface active material which is a mixture of monoalkyl suliosuccinates having the formula mmaLcooM REFERENCES crrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,181,087 Caryl et al Nov. 21. 1939 2,316,234 Flett Apr. 13, 1943 OTHER REFERENCES Aerosol wetting Agents, Pub. oi Amer. Cyan. and Chem. Corp., N. Y". (1941), pp. 0-13. 

